Scientific progress, positive media attention, format innovation, and increased consumer and academic focus on the gut’s role on human health have coalesced into overwhelming growth and popularity for the category, driving the expansion of probiotic products.

Bugs, particularly the good digestive ones found in probiotics, are hot these days. While crickets have been getting all of the attention in the bug world, it’s probiotics that have been the fastest growing supplement category in recent years. What’s driving this expansion? Scientific progress, positive media attention, format innovation, and increased consumer and academic focus on the gut’s role on human health have coalesced into overwhelming growth and popularity for the category.

Probiotics got their start as a natural byproduct of fermented dairy. Because they colonize the gastrointestinal tract, their benefit was first seen in the area of digestive health, specifically diarrhea. But there are some 50 different strains found in thousands of food, beverage and dietary supplement applications worldwide, and in the past dozen years, the clinical research supporting the use of these bacteria has exploded exponentially.

Beverage market pioneer Yakult, which got its start in Japan and features the strain Lactobacillus casei Shirota, was found to reduce the incidence of antibiotic-associated diarrhea. Meanwhile, the probiotic strain VSL#3—a blend of eight probiotic strains—also worked significantly. Then again, a recent human clinical trial found two probiotic strains, Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12, did not relieve antibiotic-induced diarrhea but reduced the duration.

This just goes to show each strain has specific benefits. Digging deeper, research and market developments have compared and contrasted single-strain probiotics against multi-strain blends. In a recent analysis published in the European Journal of Nutrition, researchers determined that of 16 studies comparing the efficacy of multistrain probiotics to their component strains individually, three-quarters showed the blends to be more effective.

Nearly 6,000 papers and clinical trials (and counting) on probiotics have been published in peer-reviewed journals in every developed country. Further, consumers are taking notice as they appear in foods, candies, non-dairy drinks and more to help drive market growth.

The trick is making sure that the probiotic strain properly aligns with the health benefit marketed. Dannon deserves a golf clap for informing the American public of probiotics’ role in digestive health through its Activia line—even though the company received a hefty fine for including only one-third the amount of probiotics that the published research noted. Instead of simply putting efficacious doses in the containers, Activia’s ads now state that one must consume three containers daily to get the digestive benefits.

After digestion, the next big area of probiotic benefit is immune function—about 70 percent of the body’s innate immunity is housed in the gut.

But the health benefits of probiotics show promise far afield from digestive health and immunity. The Human Microbiome Project aims to map the bacteria in humans, much like the Human Genome Project a decade ago mapped the body’s genetic ID. The number of spin-offs that ought to arise from this project will doubtlessly move the research community—and products—to areas beyond imagination today.

Mary Ellen Sanders, PhD, of the probiotics consultancy Dairy and Food Culture Technologies, notes that a developing area of research has to do with understanding the role of the gut microbiota on metabolic syndrome.

“We know that gut microbiota is different in healthy people compared with obese or diabetic subjects,” Sanders says. “What we don’t know is if this is a result of, or a consequence of, obesity or diabetes. We also don’t know if probiotic supplementation could impact the development of these conditions.”

Meanwhile, suppliers are doing a better job of highlighting and explaining the science behind probiotic benefits for gut health, making it easier for consumers to digest new science promoting benefits in other areas such as cardiovascular support and blood sugar management.

A number of finished products have been launched that showcase the most novel new applications for probiotic blends. Moving beyond traditional supplements, probiotics are showing up in beverages, foods, personal care and other markets, which continue to diversify the ingredient.

So while probiotics continue to dominate sales in the supplements aisles, their promise is just beginning to unfold. More research is clearly needed to delineate the precise health benefits of specific probiotic strains. In too many instances, probiotic products use a general blend of strains with marketing messages that might—or might not—align with the research. In a decade’s time, the research will catch up to the marketing, and we should have a much better handle on the great diversity of health benefits bacteria can have on our health. Stay tuned.